YORKSHIRE captain David Byas wants his players to keep their composure when they take on Warwickshire in the quarter-finals of the Cheltenham & Gloucester Trophy at Headingley tomorrow.

Byas admitted his side still has room for improvement despite their impressive victory over Surrey in the fourth round - and a crushing Norwich Union National League victory over Warwickshire yesterday.

After posting 234 for six in their limited overs, Yorkshire - without their England bowlers - tore into the Warwickshire reply and skittled the visitors for just 59.

But despite that triumph, and the fine win over Surrey, Byas still believes his side need to address weaknesses if they are to secure back-to-back wins over Warwickshire.

"The lads have been buoyed by the result against Surrey but we're still conscious of areas of weakness," he said.

"We batted brilliantly at the end but the performance in the first half of that game, when we were fielding, was woeful.

"We'll be hoping to cement our game - maybe we need to relax and chill out more.

"But it will be a difficult fixture against Warwickshire. I've not seen much of them this season but they're a wonderful one-day side and their record speaks for itself. It's anybody's game.

"This is our last chance at a one-day trophy this year so we'll be keen to succeed."

Warwickshire coach Bob Woolmer, meanwhile, claims tactics will be vital to success as the sides prepare to lock horns again following yesterday's National League day-night humiliation.

And with so much at stake, Woolmer is hoping his players will continue their recent run of good form.

He said: "It's a big game and we're playing good cricket at the moment which we want to carry forward into it.

"We'll have to pick our strategy carefully as there will be a few factors involved, like the pitch, the weather and Monday's result.

"And although Yorkshire have had something of an up-and-down season in the one-day game, they're still a very good side. I thought they were struggling against Surrey in the last round but in the end they cruised to victory.

"It's good to get to the quarter-finals in any competition and we've done pretty well in the Trophy in recent years.

"We've now got to prepare the best we can, do our homework and produce the best possible performance on the day."

Woolmer has not decided on his final 11 but revealed he expects to make "one or two changes" to the line-up that started against Yorkshire in the National League game.

The hosts will be able to call on the services of England's Craig White and Darren Gough following their involvement in the second Test defeat at Lord's.

However, Michael Vaughan and Michael Lumb have both been ruled out with knee injuries, while Matthew Hoggard is still sidelined by a stress fracture of his foot.